This invention relates to a motorcycle and more particularly to an improved sensor layout for the exhaust system of a motorcycle.
As is well known, considerable attempts are being made to reduce the pollution of undesirable exhaust gas constituents from the exhaust gases of internal combustion engines and to improve their fuel economy. These efforts are not limited to automotive applications but also apply to motorcycles. However, the problems attended with emission control on motorcycles is aggravated by the extremely compact nature of such vehicles and also the fact that the running components of motorcycles are generally exposed to the atmosphere and may be subject to damage.
Specifically, it has been proposed to employ not only catalytic treatment for the exhaust gases of motorcycle engines but also to employ various sensors that protrude into the exhaust system for sensing the combustion conditions of the engine. For example, the use of oxygen sensors in the exhaust system is particularly desirable for combustion control. However, the sensor in addition to protruding into the exhaust system also has an exposed portion that provides the output connection for the engine control system. Usually the exhaust system in a motorcycle is disposed quite low and frequently the converter or muffler may be positioned beneath the crankcase of the engine. Hence, the sensor is exposed to damage from articles that may be thrown up by the rotation of the wheels and other foreign objects.
It addition to these problems, motorcycles are leaned when negotiating curves. This leaning operation causes the exhaust device in which the sensor is positioned to move quite close to the ground. If the sensor is positioned at a low location in the exhaust device in which it is inserted, it actually may strike the ground during these leaning operations.
It is, therefore, a principal object to this invention to provide an improved sensor arrangement for the exhaust system of a motorcycle.
It is a further object to this invention to provide a sensor arrangement for a motorcycle exhaust system wherein the sensor will be protected from foreign objects or damage upon leaning of the motorcycle.
It is a further object to this invention to provide an arrangement for positioning a sensor in the exhaust system of a motorcycle so that it will be protected by the exhaust device into which it is positioned.
As has been noted, motorcycles are extremely compact devices and the placement of the various components can present several problems. In this regard, it is a normal practice to provide an exhaust system that includes exhaust pipes that extend from the exhaust ports of the engine downwardly to deliver exhaust gases to an exhaust device which is positioned at the lower portion of the motorcycle and frequently beneath the engine of the motorcycle. For ease of assembly, it has been the practice to form the exhaust pipes and the exhaust device as a unitary assembly. However, such exhaust pipe and exhaust device placement can frequently position the exhaust pipes in an area where they obscure a component of the motorcycle which may require servicing. In order to reach this component, therefore, it is necessary to remove the complete exhaust system.
It is, therefore, a still further object to this invention to provide an improved exhaust system for a motorcycle wherein at least a portion of the exhaust system may be readily detached from the other exhaust system components which form a unitary assembly to offer ease of servicing.